jetpack compose VerticalPager with first page with different PageSize

Question

I'm trying to create a VerticalPager, where the first item in the pager is kind of a "header", therefore I want it's height to be smaller then all the other pages. so the height should be kind of "wrapped", and then the other heights should be the same.

I tried something like this but it doesn't work, and the first item is still in the same size as all the other pages:

val pagerState = rememberPagerState { it.size }
VerticalPager(
    modifier = Modifier.wrapContentHeight(),
    beyondBoundsPageCount = 0,
    pageSpacing = 22.dp,
    contentPadding = PaddingValues(horizontal = horizontalPad),
    pageSize = object : PageSize {
        override fun Density.calculateMainAxisPageSize(
        availableSpace: Int,
        pageSpacing: Int
        ): Int {
            return ((availableSpace - 2 * pageSpacing) * 0.8f).toInt()
        }
    },
    state = pagerState,
    ) { idx ->
        if (idx == 0) { ... } else { ... }
    }

maybe I can manipulate some other attrivutes in order to make the PageSize of the first item different?

thanks